[apple/xnu.git] / bsd / kern / mach_process.c

/*
 * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
/*-
 * Copyright (c) 1982, 1986, 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	from: @(#)sys_process.c	8.1 (Berkeley) 6/10/93
 */

#include <machine/reg.h>
#include <machine/psl.h>

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc_internal.h>
#include <sys/kauth.h>
#include <sys/errno.h>
#include <sys/ptrace.h>
#include <sys/uio.h>
#include <sys/user.h>
#include <sys/sysctl.h>
#include <sys/wait.h>

#include <sys/mount_internal.h>
#include <sys/sysproto.h>
#include <sys/kdebug.h>

#include <security/audit/audit.h>

#include <kern/task.h>
#include <kern/thread.h>

#include <mach/task.h>			/* for task_resume() */
#include <kern/sched_prim.h>		/* for thread_exception_return() */

#include <vm/vm_protos.h>		/* cs_allow_invalid() */

#include <pexpert/pexpert.h>

/* XXX ken/bsd_kern.c - prototype should be in common header */
int get_task_userstop(task_t);

/* Macros to clear/set/test flags. */
#define	SET(t, f)	(t) |= (f)
#define	CLR(t, f)	(t) &= ~(f)
#define	ISSET(t, f)	((t) & (f))

extern thread_t	port_name_to_thread(mach_port_name_t port_name);
extern thread_t get_firstthread(task_t);


/*
 * sys-trace system call.
 */

int
ptrace(struct proc *p, struct ptrace_args *uap, int32_t *retval)
{
	struct proc *t = current_proc();	/* target process */
	task_t		task;
	thread_t	th_act;
	struct uthread 	*ut;
	int tr_sigexc = 0;
	int error = 0;
	int stopped = 0;

	AUDIT_ARG(cmd, uap->req);
	AUDIT_ARG(pid, uap->pid);
	AUDIT_ARG(addr, uap->addr);
	AUDIT_ARG(value32, uap->data);

	if (uap->req == PT_DENY_ATTACH) {
#if (DEVELOPMENT || DEBUG) && defined(__arm__)
		if (PE_i_can_has_debugger(NULL))
			return(0);
#endif
		proc_lock(p);
		if (ISSET(p->p_lflag, P_LTRACED)) {
			proc_unlock(p);
			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_FRCEXIT) | DBG_FUNC_NONE,
					      p->p_pid, W_EXITCODE(ENOTSUP, 0), 4, 0, 0);
			exit1(p, W_EXITCODE(ENOTSUP, 0), retval);
			/* drop funnel before we return */
			thread_exception_return();
			/* NOTREACHED */
		}
		SET(p->p_lflag, P_LNOATTACH);
		proc_unlock(p);

		return(0);
	}

	if (uap->req == PT_FORCEQUOTA) {
		if (is_suser()) {
			OSBitOrAtomic(P_FORCEQUOTA, &t->p_flag);
			return (0);
		} else
			return (EPERM);
	}

	/*
	 *	Intercept and deal with "please trace me" request.
	 */	 
	if (uap->req == PT_TRACE_ME) {
		proc_lock(p);
		SET(p->p_lflag, P_LTRACED);
		/* Non-attached case, our tracer is our parent. */
		p->p_oppid = p->p_ppid;
		/* Check whether child and parent are allowed to run modified
		 * code (they'll have to) */
		struct proc *pproc=proc_find(p->p_oppid);
		proc_unlock(p);
		cs_allow_invalid(p);
		if(pproc) {
			cs_allow_invalid(pproc);
			proc_rele(pproc);
		}
		return(0);
	}
	if (uap->req == PT_SIGEXC) {
		proc_lock(p);
		if (ISSET(p->p_lflag, P_LTRACED)) {
			SET(p->p_lflag, P_LSIGEXC);
			proc_unlock(p);
			return(0);
		} else {
			proc_unlock(p);
			return(EINVAL);
		}
	}

	/* 
	 * We do not want ptrace to do anything with kernel or launchd 
	 */
	if (uap->pid < 2) {
		return(EPERM);
	}

	/*
	 *	Locate victim, and make sure it is traceable.
	 */
	if ((t = proc_find(uap->pid)) == NULL)
			return (ESRCH);

	AUDIT_ARG(process, t);

	task = t->task;
	if (uap->req == PT_ATTACHEXC) {
		uap->req = PT_ATTACH;
		tr_sigexc = 1;
	}
	if (uap->req == PT_ATTACH) {
		int		err;
		
		if ( kauth_authorize_process(proc_ucred(p), KAUTH_PROCESS_CANTRACE, 
									 t, (uintptr_t)&err, 0, 0) == 0 ) {
			/* it's OK to attach */
			proc_lock(t);
			SET(t->p_lflag, P_LTRACED);
			if (tr_sigexc) 
				SET(t->p_lflag, P_LSIGEXC);
	
			t->p_oppid = t->p_ppid;
			/* Check whether child and parent are allowed to run modified
			 * code (they'll have to) */
			proc_unlock(t);
			cs_allow_invalid(t);
			cs_allow_invalid(p);
			if (t->p_pptr != p)
				proc_reparentlocked(t, p, 1, 0);
	
			proc_lock(t);
			if (get_task_userstop(task) > 0 ) {
				stopped = 1;
			}
			t->p_xstat = 0;
			proc_unlock(t);
			psignal(t, SIGSTOP);
			/*
			 * If the process was stopped, wake up and run through
			 * issignal() again to properly connect to the tracing
			 * process.
			 */
			if (stopped)
				task_resume(task);       
			error = 0;
			goto out;
		}
		else {
			/* not allowed to attach, proper error code returned by kauth_authorize_process */
			if (ISSET(t->p_lflag, P_LNOATTACH)) {
				psignal(p, SIGSEGV);
			}
			
			error = err;
			goto out;
		}
	}

	/*
	 * You can't do what you want to the process if:
	 *	(1) It's not being traced at all,
	 */
	proc_lock(t);
	if (!ISSET(t->p_lflag, P_LTRACED)) {
		proc_unlock(t);
		error = EPERM;
		goto out;
	}

	/*
	 *	(2) it's not being traced by _you_, or
	 */
	if (t->p_pptr != p) {
		proc_unlock(t);
		error = EBUSY;
		goto out;
	}

	/*
	 *	(3) it's not currently stopped.
	 */
	if (t->p_stat != SSTOP) {
		proc_unlock(t);
		error = EBUSY;
		goto out;
	}

	/*
	 *	Mach version of ptrace executes request directly here,
	 *	thus simplifying the interaction of ptrace and signals.
	 */
	/* proc lock is held here */
	switch (uap->req) {

	case PT_DETACH:
		if (t->p_oppid != t->p_ppid) {
			struct proc *pp;

			proc_unlock(t);
			pp = proc_find(t->p_oppid);
			proc_reparentlocked(t, pp ? pp : initproc, 1, 0);
			if (pp != PROC_NULL)
				proc_rele(pp);
			proc_lock(t);
			
		}

		t->p_oppid = 0;
		CLR(t->p_lflag, P_LTRACED);
		CLR(t->p_lflag, P_LSIGEXC);
		proc_unlock(t);
		goto resume;
		
	case PT_KILL:
		/*
		 *	Tell child process to kill itself after it
		 *	is resumed by adding NSIG to p_cursig. [see issig]
		 */
		proc_unlock(t);
		psignal(t, SIGKILL);
		goto resume;

	case PT_STEP:			/* single step the child */
	case PT_CONTINUE:		/* continue the child */
		proc_unlock(t);
		th_act = (thread_t)get_firstthread(task);
		if (th_act == THREAD_NULL) {
			error = EINVAL;
			goto out;
		}

		if (uap->addr != (user_addr_t)1) {
#if defined(ppc)
#define ALIGNED(addr,size)	(((unsigned)(addr)&((size)-1))==0)
			if (!ALIGNED((int)uap->addr, sizeof(int)))
				return (ERESTART);
#undef 	ALIGNED
#endif
			thread_setentrypoint(th_act, uap->addr);
		}

		if ((unsigned)uap->data >= NSIG) {
			error = EINVAL;
			goto out;
		}

		if (uap->data != 0) {
			psignal(t, uap->data);
                }

		if (uap->req == PT_STEP) {
		        /*
			 * set trace bit
			 */
			if (thread_setsinglestep(th_act, 1) != KERN_SUCCESS) {
				error = ENOTSUP;
				goto out;
			}
		} else {
		        /*
			 * clear trace bit if on
			 */
			if (thread_setsinglestep(th_act, 0) != KERN_SUCCESS) {
				error = ENOTSUP;
				goto out;
			}
		}	
	resume:
		proc_lock(t);
		t->p_xstat = uap->data;
		t->p_stat = SRUN;
		if (t->sigwait) {
			wakeup((caddr_t)&(t->sigwait));
			proc_unlock(t);
			if ((t->p_lflag & P_LSIGEXC) == 0) {
				task_resume(task);
			}
		} else
			proc_unlock(t);
			
		break;
		
	case PT_THUPDATE:  {
		proc_unlock(t);
		if ((unsigned)uap->data >= NSIG) {
			error = EINVAL;
			goto out;
		}
		th_act = port_name_to_thread(CAST_MACH_PORT_TO_NAME(uap->addr));
		if (th_act == THREAD_NULL)
			return (ESRCH);
		ut = (uthread_t)get_bsdthread_info(th_act);
		if (uap->data)
			ut->uu_siglist |= sigmask(uap->data);
		proc_lock(t);
		t->p_xstat = uap->data;
		t->p_stat = SRUN;
		proc_unlock(t);
		thread_deallocate(th_act);
		error = 0;
		}
		break;
	default:
		proc_unlock(t);
		error = EINVAL;
		goto out;
	}

	error = 0;
out:
	proc_rele(t);
	return(error);
}


/*
 * determine if one process (cur_procp) can trace another process (traced_procp).
 */

int
cantrace(proc_t cur_procp, kauth_cred_t creds, proc_t traced_procp, int *errp)
{
	int		my_err;
	/*
	 * You can't trace a process if:
	 *	(1) it's the process that's doing the tracing,
	 */
	if (traced_procp->p_pid == cur_procp->p_pid) {
		*errp = EINVAL;
		return (0);
	}

	/*
	 *	(2) it's already being traced, or
	 */
	if (ISSET(traced_procp->p_lflag, P_LTRACED)) {
		*errp = EBUSY;
		return (0);
	}

	/*
	 *	(3) it's not owned by you, or is set-id on exec
	 *	    (unless you're root).
	 */
	if ((kauth_cred_getruid(creds) != kauth_cred_getruid(proc_ucred(traced_procp)) ||
		ISSET(traced_procp->p_flag, P_SUGID)) &&
		(my_err = suser(creds, &cur_procp->p_acflag)) != 0) {
		*errp = my_err;
		return (0);
	}

	if ((cur_procp->p_lflag & P_LTRACED) && isinferior(cur_procp, traced_procp)) {
		*errp = EPERM;
		return (0);
	}

	if (ISSET(traced_procp->p_lflag, P_LNOATTACH)) {
		*errp = EBUSY;
		return (0);
	}
	return(1);
}
Commit	Line	Data
1c79356b	1	/*
2d21ac55	2	* Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
5d5c5d0d	3	*
2d21ac55	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
1c79356b	5	*
2d21ac55 A	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
8f6c56a5	14	*
2d21ac55 A	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
8f6c56a5 A	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
8f6c56a5 A	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
2d21ac55 A	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
8f6c56a5	25	*
2d21ac55	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
1c79356b A	27	*/
	28	/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
	29	/*-
	30	* Copyright (c) 1982, 1986, 1989, 1993
	31	* The Regents of the University of California. All rights reserved.
	32	* (c) UNIX System Laboratories, Inc.
	33	* All or some portions of this file are derived from material licensed
	34	* to the University of California by American Telephone and Telegraph
	35	* Co. or Unix System Laboratories, Inc. and are reproduced herein with
	36	* the permission of UNIX System Laboratories, Inc.
	37	*
	38	* Redistribution and use in source and binary forms, with or without
	39	* modification, are permitted provided that the following conditions
	40	* are met:
	41	* 1. Redistributions of source code must retain the above copyright
	42	* notice, this list of conditions and the following disclaimer.
	43	* 2. Redistributions in binary form must reproduce the above copyright
	44	* notice, this list of conditions and the following disclaimer in the
	45	* documentation and/or other materials provided with the distribution.
	46	* 3. All advertising materials mentioning features or use of this software
	47	* must display the following acknowledgement:
	48	* This product includes software developed by the University of
	49	* California, Berkeley and its contributors.
	50	* 4. Neither the name of the University nor the names of its contributors
	51	* may be used to endorse or promote products derived from this software
	52	* without specific prior written permission.
	53	*
	54	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	55	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	56	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	57	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	58	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	59	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	60	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	61	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	62	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	63	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	64	* SUCH DAMAGE.
	65	*
	66	* from: @(#)sys_process.c 8.1 (Berkeley) 6/10/93
	67	*/
1c79356b A	68
	69	#include <machine/reg.h>
	70	#include <machine/psl.h>
	71
	72	#include <sys/param.h>
	73	#include <sys/systm.h>
91447636 A	74	#include <sys/proc_internal.h>
91447636 A	75	#include <sys/kauth.h>
1c79356b A	76	#include <sys/errno.h>
	77	#include <sys/ptrace.h>
	78	#include <sys/uio.h>
	79	#include <sys/user.h>
	80	#include <sys/sysctl.h>
0b4e3aa0	81	#include <sys/wait.h>
1c79356b	82
91447636 A	83	#include <sys/mount_internal.h>
91447636 A	84	#include <sys/sysproto.h>
b0d623f7	85	#include <sys/kdebug.h>
1c79356b	86
b0d623f7	87	#include <security/audit/audit.h>
e5568f75	88
1c79356b A	89	#include <kern/task.h>
1c79356b A	90	#include <kern/thread.h>
1c79356b	91
2d21ac55 A	92	#include <mach/task.h> /* for task_resume() */
	93	#include <kern/sched_prim.h> /* for thread_exception_return() */
	94
b0d623f7 A	95	#include <vm/vm_protos.h> /* cs_allow_invalid() */
b0d623f7 A	96
6d2010ae A	97	#include <pexpert/pexpert.h>
6d2010ae A	98
2d21ac55 A	99	/* XXX ken/bsd_kern.c - prototype should be in common header */
2d21ac55 A	100	int get_task_userstop(task_t);
91447636	101
1c79356b A	102	/* Macros to clear/set/test flags. */
	103	#define SET(t, f) (t) \|= (f)
	104	#define CLR(t, f) (t) &= ~(f)
	105	#define ISSET(t, f) ((t) & (f))
	106
91447636	107	extern thread_t port_name_to_thread(mach_port_name_t port_name);
91447636 A	108	extern thread_t get_firstthread(task_t);
91447636 A	109
9bccf70c	110
1c79356b A	111	/*
	112	* sys-trace system call.
	113	*/
9bccf70c	114
1c79356b	115	int
b0d623f7	116	ptrace(struct proc p, struct ptrace_args uap, int32_t *retval)
1c79356b A	117	{
1c79356b A	118	struct proc t = current_proc(); / target process */
1c79356b	119	task_t task;
91447636	120	thread_t th_act;
1c79356b	121	struct uthread *ut;
9bccf70c	122	int tr_sigexc = 0;
2d21ac55 A	123	int error = 0;
2d21ac55 A	124	int stopped = 0;
1c79356b	125
e5568f75 A	126	AUDIT_ARG(cmd, uap->req);
	127	AUDIT_ARG(pid, uap->pid);
	128	AUDIT_ARG(addr, uap->addr);
b0d623f7	129	AUDIT_ARG(value32, uap->data);
1c79356b	130
91447636	131	if (uap->req == PT_DENY_ATTACH) {
6d2010ae A	132	#if (DEVELOPMENT \|\| DEBUG) && defined(__arm__)
	133	if (PE_i_can_has_debugger(NULL))
	134	return(0);
	135	#endif
2d21ac55 A	136	proc_lock(p);
	137	if (ISSET(p->p_lflag, P_LTRACED)) {
	138	proc_unlock(p);
b0d623f7 A	139	KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_FRCEXIT) \| DBG_FUNC_NONE,
b0d623f7 A	140	p->p_pid, W_EXITCODE(ENOTSUP, 0), 4, 0, 0);
91447636 A	141	exit1(p, W_EXITCODE(ENOTSUP, 0), retval);
91447636 A	142	/* drop funnel before we return */
91447636 A	143	thread_exception_return();
	144	/* NOTREACHED */
	145	}
2d21ac55 A	146	SET(p->p_lflag, P_LNOATTACH);
2d21ac55 A	147	proc_unlock(p);
0b4e3aa0 A	148
	149	return(0);
	150	}
	151
9bccf70c A	152	if (uap->req == PT_FORCEQUOTA) {
9bccf70c A	153	if (is_suser()) {
b0d623f7	154	OSBitOrAtomic(P_FORCEQUOTA, &t->p_flag);
9bccf70c A	155	return (0);
	156	} else
	157	return (EPERM);
	158	}
	159
1c79356b A	160	/*
	161	* Intercept and deal with "please trace me" request.
	162	*/
	163	if (uap->req == PT_TRACE_ME) {
2d21ac55 A	164	proc_lock(p);
2d21ac55 A	165	SET(p->p_lflag, P_LTRACED);
1c79356b	166	/* Non-attached case, our tracer is our parent. */
2d21ac55	167	p->p_oppid = p->p_ppid;
b0d623f7 A	168	/* Check whether child and parent are allowed to run modified
	169	* code (they'll have to) */
	170	struct proc *pproc=proc_find(p->p_oppid);
2d21ac55	171	proc_unlock(p);
b0d623f7	172	cs_allow_invalid(p);
6d2010ae A	173	if(pproc) {
	174	cs_allow_invalid(pproc);
	175	proc_rele(pproc);
	176	}
1c79356b A	177	return(0);
1c79356b A	178	}
9bccf70c	179	if (uap->req == PT_SIGEXC) {
2d21ac55 A	180	proc_lock(p);
	181	if (ISSET(p->p_lflag, P_LTRACED)) {
	182	SET(p->p_lflag, P_LSIGEXC);
	183	proc_unlock(p);
9bccf70c	184	return(0);
2d21ac55 A	185	} else {
2d21ac55 A	186	proc_unlock(p);
9bccf70c	187	return(EINVAL);
2d21ac55 A	188	}
	189	}
	190
	191	/*
	192	* We do not want ptrace to do anything with kernel or launchd
	193	*/
	194	if (uap->pid < 2) {
	195	return(EPERM);
9bccf70c	196	}
1c79356b A	197
	198	/*
	199	* Locate victim, and make sure it is traceable.
	200	*/
2d21ac55	201	if ((t = proc_find(uap->pid)) == NULL)
1c79356b A	202	return (ESRCH);
1c79356b A	203
e5568f75 A	204	AUDIT_ARG(process, t);
e5568f75 A	205
1c79356b	206	task = t->task;
9bccf70c A	207	if (uap->req == PT_ATTACHEXC) {
	208	uap->req = PT_ATTACH;
	209	tr_sigexc = 1;
	210	}
1c79356b	211	if (uap->req == PT_ATTACH) {
91447636 A	212	int err;
	213
	214	if ( kauth_authorize_process(proc_ucred(p), KAUTH_PROCESS_CANTRACE,
	215	t, (uintptr_t)&err, 0, 0) == 0 ) {
	216	/* it's OK to attach */
2d21ac55 A	217	proc_lock(t);
2d21ac55 A	218	SET(t->p_lflag, P_LTRACED);
91447636	219	if (tr_sigexc)
2d21ac55	220	SET(t->p_lflag, P_LSIGEXC);
91447636	221
2d21ac55	222	t->p_oppid = t->p_ppid;
b0d623f7 A	223	/* Check whether child and parent are allowed to run modified
b0d623f7 A	224	* code (they'll have to) */
2d21ac55	225	proc_unlock(t);
b0d623f7 A	226	cs_allow_invalid(t);
b0d623f7 A	227	cs_allow_invalid(p);
91447636	228	if (t->p_pptr != p)
2d21ac55	229	proc_reparentlocked(t, p, 1, 0);
91447636	230
2d21ac55 A	231	proc_lock(t);
	232	if (get_task_userstop(task) > 0 ) {
	233	stopped = 1;
91447636	234	}
2d21ac55 A	235	t->p_xstat = 0;
	236	proc_unlock(t);
	237	psignal(t, SIGSTOP);
	238	/*
	239	* If the process was stopped, wake up and run through
	240	* issignal() again to properly connect to the tracing
	241	* process.
	242	*/
	243	if (stopped)
	244	task_resume(task);
	245	error = 0;
	246	goto out;
0b4e3aa0	247	}
91447636 A	248	else {
91447636 A	249	/* not allowed to attach, proper error code returned by kauth_authorize_process */
2d21ac55	250	if (ISSET(t->p_lflag, P_LNOATTACH)) {
91447636 A	251	psignal(p, SIGSEGV);
91447636 A	252	}
2d21ac55 A	253
	254	error = err;
	255	goto out;
1c79356b	256	}
1c79356b A	257	}
	258
	259	/*
	260	* You can't do what you want to the process if:
	261	* (1) It's not being traced at all,
	262	*/
2d21ac55 A	263	proc_lock(t);
	264	if (!ISSET(t->p_lflag, P_LTRACED)) {
	265	proc_unlock(t);
	266	error = EPERM;
	267	goto out;
	268	}
1c79356b A	269
	270	/*
	271	* (2) it's not being traced by _you_, or
	272	*/
2d21ac55 A	273	if (t->p_pptr != p) {
	274	proc_unlock(t);
	275	error = EBUSY;
	276	goto out;
	277	}
1c79356b A	278
	279	/*
	280	* (3) it's not currently stopped.
	281	*/
2d21ac55 A	282	if (t->p_stat != SSTOP) {
	283	proc_unlock(t);
	284	error = EBUSY;
	285	goto out;
	286	}
1c79356b A	287
	288	/*
	289	* Mach version of ptrace executes request directly here,
	290	* thus simplifying the interaction of ptrace and signals.
	291	*/
2d21ac55	292	/* proc lock is held here */
1c79356b A	293	switch (uap->req) {
	294
	295	case PT_DETACH:
2d21ac55	296	if (t->p_oppid != t->p_ppid) {
1c79356b A	297	struct proc *pp;
1c79356b A	298
2d21ac55 A	299	proc_unlock(t);
	300	pp = proc_find(t->p_oppid);
	301	proc_reparentlocked(t, pp ? pp : initproc, 1, 0);
	302	if (pp != PROC_NULL)
	303	proc_rele(pp);
	304	proc_lock(t);
	305
1c79356b A	306	}
	307
	308	t->p_oppid = 0;
2d21ac55 A	309	CLR(t->p_lflag, P_LTRACED);
	310	CLR(t->p_lflag, P_LSIGEXC);
	311	proc_unlock(t);
1c79356b A	312	goto resume;
	313
	314	case PT_KILL:
	315	/*
	316	* Tell child process to kill itself after it
	317	* is resumed by adding NSIG to p_cursig. [see issig]
	318	*/
2d21ac55 A	319	proc_unlock(t);
2d21ac55 A	320	psignal(t, SIGKILL);
1c79356b A	321	goto resume;
	322
	323	case PT_STEP: /* single step the child */
	324	case PT_CONTINUE: /* continue the child */
2d21ac55	325	proc_unlock(t);
91447636	326	th_act = (thread_t)get_firstthread(task);
2d21ac55 A	327	if (th_act == THREAD_NULL) {
	328	error = EINVAL;
	329	goto out;
	330	}
0c530ab8	331
91447636	332	if (uap->addr != (user_addr_t)1) {
0c530ab8	333	#if defined(ppc)
1c79356b	334	#define ALIGNED(addr,size) (((unsigned)(addr)&((size)-1))==0)
2d21ac55 A	335	if (!ALIGNED((int)uap->addr, sizeof(int)))
2d21ac55 A	336	return (ERESTART);
1c79356b	337	#undef ALIGNED
1c79356b	338	#endif
2d21ac55	339	thread_setentrypoint(th_act, uap->addr);
0c530ab8	340	}
1c79356b	341
2d21ac55 A	342	if ((unsigned)uap->data >= NSIG) {
	343	error = EINVAL;
	344	goto out;
	345	}
1c79356b A	346
1c79356b A	347	if (uap->data != 0) {
2d21ac55	348	psignal(t, uap->data);
1c79356b	349	}
1c79356b A	350
1c79356b A	351	if (uap->req == PT_STEP) {
0c530ab8 A	352	/*
	353	* set trace bit
	354	*/
2d21ac55 A	355	if (thread_setsinglestep(th_act, 1) != KERN_SUCCESS) {
	356	error = ENOTSUP;
	357	goto out;
	358	}
0c530ab8 A	359	} else {
	360	/*
	361	* clear trace bit if on
	362	*/
2d21ac55 A	363	if (thread_setsinglestep(th_act, 0) != KERN_SUCCESS) {
	364	error = ENOTSUP;
	365	goto out;
	366	}
	367	}
1c79356b	368	resume:
2d21ac55	369	proc_lock(t);
1c79356b A	370	t->p_xstat = uap->data;
	371	t->p_stat = SRUN;
	372	if (t->sigwait) {
	373	wakeup((caddr_t)&(t->sigwait));
2d21ac55 A	374	proc_unlock(t);
	375	if ((t->p_lflag & P_LSIGEXC) == 0) {
	376	task_resume(task);
	377	}
	378	} else
	379	proc_unlock(t);
	380
1c79356b A	381	break;
1c79356b A	382
9bccf70c	383	case PT_THUPDATE: {
2d21ac55 A	384	proc_unlock(t);
	385	if ((unsigned)uap->data >= NSIG) {
	386	error = EINVAL;
	387	goto out;
	388	}
b0d623f7	389	th_act = port_name_to_thread(CAST_MACH_PORT_TO_NAME(uap->addr));
91447636	390	if (th_act == THREAD_NULL)
9bccf70c A	391	return (ESRCH);
	392	ut = (uthread_t)get_bsdthread_info(th_act);
	393	if (uap->data)
	394	ut->uu_siglist \|= sigmask(uap->data);
2d21ac55	395	proc_lock(t);
9bccf70c A	396	t->p_xstat = uap->data;
9bccf70c A	397	t->p_stat = SRUN;
2d21ac55	398	proc_unlock(t);
91447636	399	thread_deallocate(th_act);
2d21ac55	400	error = 0;
9bccf70c A	401	}
9bccf70c A	402	break;
1c79356b	403	default:
2d21ac55 A	404	proc_unlock(t);
	405	error = EINVAL;
	406	goto out;
1c79356b	407	}
9bccf70c	408
2d21ac55 A	409	error = 0;
	410	out:
	411	proc_rele(t);
	412	return(error);
1c79356b A	413	}
1c79356b A	414
91447636 A	415
	416	/*
	417	* determine if one process (cur_procp) can trace another process (traced_procp).
	418	*/
	419
	420	int
	421	cantrace(proc_t cur_procp, kauth_cred_t creds, proc_t traced_procp, int *errp)
	422	{
	423	int my_err;
	424	/*
	425	* You can't trace a process if:
	426	* (1) it's the process that's doing the tracing,
	427	*/
	428	if (traced_procp->p_pid == cur_procp->p_pid) {
	429	*errp = EINVAL;
	430	return (0);
	431	}
	432
	433	/*
	434	* (2) it's already being traced, or
	435	*/
2d21ac55	436	if (ISSET(traced_procp->p_lflag, P_LTRACED)) {
91447636 A	437	*errp = EBUSY;
	438	return (0);
	439	}
	440
	441	/*
	442	* (3) it's not owned by you, or is set-id on exec
	443	* (unless you're root).
	444	*/
6d2010ae	445	if ((kauth_cred_getruid(creds) != kauth_cred_getruid(proc_ucred(traced_procp)) \|\|
91447636 A	446	ISSET(traced_procp->p_flag, P_SUGID)) &&
	447	(my_err = suser(creds, &cur_procp->p_acflag)) != 0) {
	448	*errp = my_err;
	449	return (0);
	450	}
	451
2d21ac55	452	if ((cur_procp->p_lflag & P_LTRACED) && isinferior(cur_procp, traced_procp)) {
91447636 A	453	*errp = EPERM;
	454	return (0);
	455	}
	456
2d21ac55	457	if (ISSET(traced_procp->p_lflag, P_LNOATTACH)) {
91447636 A	458	*errp = EBUSY;
	459	return (0);
	460	}
	461	return(1);
	462	}